Watch uses unsigned chars to be 8bit clean

Taken from the Debian patch watch_8bitchar

watch.c

@@ -296,9 +296,9 @@ main(int argc, char *argv[])
 				move(y, x);
 				if (option_differences) {
 					chtype oldch = inch();
-					char oldc = oldch & A_CHARTEXT;
+					unsigned char oldc = oldch & A_CHARTEXT;
 					attr = !first_screen
-					    && ((char)c != oldc
+					    && ((unsigned char)c != oldc
 						||
 						(option_differences_cumulative
 						 && (oldch & A_ATTRIBUTES)));